Phil. Chuck. Jimmy. Here's why many Groundhog Day prognosticators are male

The stars of Groundhog Day go by many names: Punxsutawney Phil, Staten Island Chuck, Buckeye Chuck. And Feb. 2 is those groundhogs' day — their time to shine on an international stage. So why are male groundhogs the center of attention?

Put simply, "males emerge first" from the groundhogs' winter hibernation, biology professor Christine Maher from the University of Southern Maine told NPR.

"Once females emerge, usually a couple weeks after males do, then breeding season commences," she added.

For many U.S. states, the timing of the males' emergence syncs up well with the halfway point between the winter solstice and the spring equinox. The ancient celebrations of that halfway point would eventually become the inspiration for Groundhog Day.

Because the groundhogs' emergence is one of the earliest signs of the start of spring, people look to Punxsutawney Phil and his kin for clues about winter's end. By tradition, if the animal sees its shadow, winter will last another six weeks. If it doesn't, we can expect an early spring.

While males emerge first in Pennsylvania, "females in our area are also out by Feb. 2," groundhog expert Stam M. Zervanos, a professor emeritus of biology at Penn State Berks, told NPR.

"As you know," he added, "neither truly predicts the weather."

Both Zervanos and Maher say it's possible that in some cases, groundhogs that are presumed to be male could actually be female: "Not easy to tell unless you are close up," Zervanos said.

Some prognosticating groundhogs are female

"I suppose that if kept in captivity, it's possible for a female to arouse from hibernation earlier than we'd expect in the wild," Maher said when asked about female groundhogs being highlighted on Groundhog Day.

She has been studying the behavior of groundhogs, or woodchucks, for more than 25 years — but, Maher cautions, she is "not in tune with all the Groundhog Day celebrities."

It's understandable: The Groundhog Day field has grown since the eponymous 1993 film made the day more popular. One recent tally counted dozens of prognosticating animals in the U.S. and Canada.

Some areas do celebrate female groundhogs — and they're claimed to be more accurate than Punxsutawney Phil (more on that below). There's Gertie the Groundhog in Hanna City, Ill., for instance, and Woody the Woodchuck of Marion Township, Michigan.

Some of the female animals (or their namesakes) have been predicting when winter will end for decades. Others only recently got started: In New Jersey, Lady Edwina of Essex County has been in the prediction game since just 2022, when she took over for the retired Essex Ed.

Female groundhogs' handlers say they're more accurate than Phil

In Massachusetts, officials tout Ms. G's accuracy rate of 64%, which bests Punxsutawney Phil. The most famous groundhog's accuracy rate in recent years is around 40%, the National Oceanic and Atmospheric Administration said in 2023.

And Woody's handlers at the Howell Nature Center in Michigan say she has been right nearly 70% of the time since 1999, when she began predicting winter's end date.

Gertie the Groundhog has been making predictions in Illinois since 1993, and according to the Wildlife Prairie Park in Hanna City, she has been more accurate than Phil over that span.

While it's true in general that male groundhogs emerge from hibernation before females, the timing of that event in relation to the Feb. 2 holiday differs.

"In some parts of the country, i.e., the South, females could be out [in early February]," Maher said. "However, in the more northern parts of their range, it would just be males."

Why do the males get moving early?

They're looking for a potential mate, preparing for the spring breeding season.

"Males visit females in burrows once females have emerged from hibernation," Maher said. "Woodchucks plug their burrows with leaves and other material when they enter hibernation. Thus, they need to dig out first. Once females emerge, usually a couple weeks after males do, then breeding season commences."

Sometimes, the interactions start even earlier. In a university study that Zervanos led at Penn State Berks, early-rising male woodchucks were spotted visiting females' burrows. The groundhogs seemed to be seeking a way to connect before the mating season.

"You can call it a slumber party," Zervanos told NPR. "They are both out at this time at our latitude to reestablish bonds in preparation for mating in a few weeks."

In general, Maher said, she has found that groundhogs are more social than what was once assumed.

"Some juveniles don't leave home in their first summer, and some never leave home!" she said. "They will settle near their kin, which also live nearby, and continue to interact with those relatives throughout their lives."

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